This is a touchy issue with friends who may feel that you are butting in. If you know that they are diligent about taking the baby to well-baby visits, I'm sure the ped. will catch it, but if not, then you've got it on your conscience to make sure that either they take the baby to the doctor or you call DSS. If the baby was growing and thriving, that's one thing, since all babies are different with schedules, but this baby has hardly even gained anything! You could certainly approach your friend and let her know that you are really concerned and not just trying to butt in, but also that you feel you have a responsibility to her baby. Give her the chance to do the right thing before making the choice to call Social Services. I'm a mom of 6, and all my babies were way over this weight by 6 weeks, even my smaller ones, and none of them went longer than four hours without eating. Although I've heard that formula takes longer to digest than breastmilk. But still, the real issue is whether the baby is thriving, and it doesn't sound like this baby is. Maybe you should hook your friend up with this site, and show her the posts, or even have her post it herself. Might make a difference, knowing it's not just coming from you.